1. Field of the Invention
The present invention relates to a file delete method and a file open method, and more specifically to a file delete method used with a condition specified and a file open method as preprocessing of file processing (for example, a file preview process) performed with a condition specified.
2. Description of the Related Art
There is a FAT file system as one of the middleware provided between an application and a device driver. For example, the non-patent document 1 describes processes such as a process of reading a directory entry in the FAT file system, etc. There also is the non-patent document 2 as a specification of a FAT file system. A FAT is short for file allocation tables, and a FAT file system refers to a file system used by the OS of Microsoft such as MS-DOS, Windows (registered trademark), etc.
For example, a digital camera has been able to store an image file of several tens of thousands of orders in the storage medium having a greatly increasing amount of capability of a storage medium (also referred to as secondary storage). Correspondingly, it has become necessary to have a digital camera having the function of reading an image having a specific condition to the storage medium, smoothly previewing the image, and deleting an image which is stored in the storage medium and has a specific condition.    [Non-patent Document 1] “Practical Study of Demanded File System”, Interface, July 2001, pp 55-134    [Non-patent Document 2] “Microsoft Extensible Firmware Initiative FAT 32 File System Specification”, Hardware White Paper, Microsoft Corporation
However, in the above-mentioned FAT file system, when an image file is opened as preprocessing of image preview, or a file is deleted in the file delete process, the contents of a directory are sequentially searched to designate the position of a file. Therefore, when there are a large number of files to be processed, the searching time in the directory greatly increases.